Positive crankcase ventilation (PCV) systems may be included in engines to reduce emissions of blow-by gasses from the crankcase. PCV systems may include a conduits providing fresh intake air into the crankcase and flowing crankcase gasses including blow-by gasses into the intake system. Routing the blow-by gasses back into the intake system for subsequent combustion reduces engine emissions. Consequently, the engine's environmental impact is reduced.
U.S. Pat. No. 8,267,073 discloses a PCV system flowing blow-by gases from a crankcase into an intake system to reduce emission. The PCV system includes condensate grooves integrated into an intake conduit in an attempt to guide condensate flowing from a PCV outlet opening into the intake conduit.
However, the inventors have recognized several drawbacks with the PCV system disclosed in U.S. Pat. No. 8,267,073. For instance, ice may form in the condensation grooves during engine shutdown. As a result, downstream components such as a throttle may become damaged when the engine is started up again. Moreover, the grooves may not trap enough of the condensate formed in the intake conduit. Consequently, combustion operation may be degraded due to the presence of condensate in the intake air. Further still, the grooves may increase losses in the PCV system disclosed in U.S. Pat. No. 8,267,073.
The inventors herein have recognized the above issues and developed an engine system. The engine system includes an intake conduit positioned upstream of an engine cylinder and also includes a PCV outlet opening into the intake conduit. The engine system further includes a condensate bypass duct in parallel fluidic communication with and vertically below the intake conduit, the condensate bypass duct including a duct inlet opening into the intake conduit and a duct outlet opening into the intake conduit.
The position of the condensate bypass duct relative to the intake conduit enables the condensate bypass duct to collect condensate from the intake conduit, such as condensate generated in a PCV system and flowing from the PCV outlet. As a result, condensate may be trapped in the bypass duct, thereby reducing the likelihood of condensate flowing in a liquid or solid form from the intake conduit to downstream components such as a throttle and/or compressor. Therefore, the likelihood of component degradation from ice is reduced. Moreover, combustion operation may be improved due to the reduction in condensate flowed into the engine cylinder. In one example, the diameter of the condensate bypass duct reduces in a downstream direction. This additional opening aids in the collection of condensate in the bypass duct while the reduced orifice size controls the release of the condensate back into the airflow at a desired rate, such as a rate that does not degrade engine performance.
It will be appreciated that the condensate bypass duct may receive condensate from the intake conduit due to its location below one of the sources of condensation (i.e., the PCV outlet). As a result, the likelihood of liquid or solid condensate flowing to downstream components, such as a throttle and/or compressor, is reduced, thereby increasing component longevity and improving combustion operation. Thus, the technical result achieved via the aforementioned engine system may include increasing the system's longevity and improving combustion operation in the engine.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure. Additionally, the above issues have been recognized by the inventors herein, and are not admitted to be known.